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Diffstat (limited to 'kernel/drivers/scsi/atari_NCR5380.c')
-rw-r--r--kernel/drivers/scsi/atari_NCR5380.c2927
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diff --git a/kernel/drivers/scsi/atari_NCR5380.c b/kernel/drivers/scsi/atari_NCR5380.c
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index 000000000..db87ece6e
--- /dev/null
+++ b/kernel/drivers/scsi/atari_NCR5380.c
@@ -0,0 +1,2927 @@
+/*
+ * NCR 5380 generic driver routines. These should make it *trivial*
+ * to implement 5380 SCSI drivers under Linux with a non-trantor
+ * architecture.
+ *
+ * Note that these routines also work with NR53c400 family chips.
+ *
+ * Copyright 1993, Drew Eckhardt
+ * Visionary Computing
+ * (Unix and Linux consulting and custom programming)
+ * drew@colorado.edu
+ * +1 (303) 666-5836
+ *
+ * For more information, please consult
+ *
+ * NCR 5380 Family
+ * SCSI Protocol Controller
+ * Databook
+ *
+ * NCR Microelectronics
+ * 1635 Aeroplaza Drive
+ * Colorado Springs, CO 80916
+ * 1+ (719) 578-3400
+ * 1+ (800) 334-5454
+ */
+
+/*
+ * ++roman: To port the 5380 driver to the Atari, I had to do some changes in
+ * this file, too:
+ *
+ * - Some of the debug statements were incorrect (undefined variables and the
+ * like). I fixed that.
+ *
+ * - In information_transfer(), I think a #ifdef was wrong. Looking at the
+ * possible DMA transfer size should also happen for REAL_DMA. I added this
+ * in the #if statement.
+ *
+ * - When using real DMA, information_transfer() should return in a DATAOUT
+ * phase after starting the DMA. It has nothing more to do.
+ *
+ * - The interrupt service routine should run main after end of DMA, too (not
+ * only after RESELECTION interrupts). Additionally, it should _not_ test
+ * for more interrupts after running main, since a DMA process may have
+ * been started and interrupts are turned on now. The new int could happen
+ * inside the execution of NCR5380_intr(), leading to recursive
+ * calls.
+ *
+ * - I've added a function merge_contiguous_buffers() that tries to
+ * merge scatter-gather buffers that are located at contiguous
+ * physical addresses and can be processed with the same DMA setup.
+ * Since most scatter-gather operations work on a page (4K) of
+ * 4 buffers (1K), in more than 90% of all cases three interrupts and
+ * DMA setup actions are saved.
+ *
+ * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
+ * and USLEEP, because these were messing up readability and will never be
+ * needed for Atari SCSI.
+ *
+ * - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
+ * stuff), and 'main' is executed in a bottom half if awoken by an
+ * interrupt.
+ *
+ * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
+ * constructs. In my eyes, this made the source rather unreadable, so I
+ * finally replaced that by the *_PRINTK() macros.
+ *
+ */
+
+/*
+ * Further development / testing that should be done :
+ * 1. Test linked command handling code after Eric is ready with
+ * the high level code.
+ */
+
+/* Adapted for the sun3 by Sam Creasey. */
+
+#include <scsi/scsi_dbg.h>
+#include <scsi/scsi_transport_spi.h>
+
+#if (NDEBUG & NDEBUG_LISTS)
+#define LIST(x, y) \
+ do { \
+ printk("LINE:%d Adding %p to %p\n", \
+ __LINE__, (void*)(x), (void*)(y)); \
+ if ((x) == (y)) \
+ udelay(5); \
+ } while (0)
+#define REMOVE(w, x, y, z) \
+ do { \
+ printk("LINE:%d Removing: %p->%p %p->%p \n", \
+ __LINE__, (void*)(w), (void*)(x), \
+ (void*)(y), (void*)(z)); \
+ if ((x) == (y)) \
+ udelay(5); \
+ } while (0)
+#else
+#define LIST(x,y)
+#define REMOVE(w,x,y,z)
+#endif
+
+#ifndef notyet
+#undef LINKED
+#endif
+
+/*
+ * Design
+ *
+ * This is a generic 5380 driver. To use it on a different platform,
+ * one simply writes appropriate system specific macros (ie, data
+ * transfer - some PC's will use the I/O bus, 68K's must use
+ * memory mapped) and drops this file in their 'C' wrapper.
+ *
+ * As far as command queueing, two queues are maintained for
+ * each 5380 in the system - commands that haven't been issued yet,
+ * and commands that are currently executing. This means that an
+ * unlimited number of commands may be queued, letting
+ * more commands propagate from the higher driver levels giving higher
+ * throughput. Note that both I_T_L and I_T_L_Q nexuses are supported,
+ * allowing multiple commands to propagate all the way to a SCSI-II device
+ * while a command is already executing.
+ *
+ *
+ * Issues specific to the NCR5380 :
+ *
+ * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
+ * piece of hardware that requires you to sit in a loop polling for
+ * the REQ signal as long as you are connected. Some devices are
+ * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
+ * while doing long seek operations.
+ *
+ * The workaround for this is to keep track of devices that have
+ * disconnected. If the device hasn't disconnected, for commands that
+ * should disconnect, we do something like
+ *
+ * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
+ *
+ * Some tweaking of N and M needs to be done. An algorithm based
+ * on "time to data" would give the best results as long as short time
+ * to datas (ie, on the same track) were considered, however these
+ * broken devices are the exception rather than the rule and I'd rather
+ * spend my time optimizing for the normal case.
+ *
+ * Architecture :
+ *
+ * At the heart of the design is a coroutine, NCR5380_main,
+ * which is started from a workqueue for each NCR5380 host in the
+ * system. It attempts to establish I_T_L or I_T_L_Q nexuses by
+ * removing the commands from the issue queue and calling
+ * NCR5380_select() if a nexus is not established.
+ *
+ * Once a nexus is established, the NCR5380_information_transfer()
+ * phase goes through the various phases as instructed by the target.
+ * if the target goes into MSG IN and sends a DISCONNECT message,
+ * the command structure is placed into the per instance disconnected
+ * queue, and NCR5380_main tries to find more work. If the target is
+ * idle for too long, the system will try to sleep.
+ *
+ * If a command has disconnected, eventually an interrupt will trigger,
+ * calling NCR5380_intr() which will in turn call NCR5380_reselect
+ * to reestablish a nexus. This will run main if necessary.
+ *
+ * On command termination, the done function will be called as
+ * appropriate.
+ *
+ * SCSI pointers are maintained in the SCp field of SCSI command
+ * structures, being initialized after the command is connected
+ * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
+ * Note that in violation of the standard, an implicit SAVE POINTERS operation
+ * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
+ */
+
+/*
+ * Using this file :
+ * This file a skeleton Linux SCSI driver for the NCR 5380 series
+ * of chips. To use it, you write an architecture specific functions
+ * and macros and include this file in your driver.
+ *
+ * These macros control options :
+ * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
+ * for commands that return with a CHECK CONDITION status.
+ *
+ * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
+ * transceivers.
+ *
+ * LINKED - if defined, linked commands are supported.
+ *
+ * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
+ *
+ * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
+ *
+ * These macros MUST be defined :
+ *
+ * NCR5380_read(register) - read from the specified register
+ *
+ * NCR5380_write(register, value) - write to the specific register
+ *
+ * NCR5380_implementation_fields - additional fields needed for this
+ * specific implementation of the NCR5380
+ *
+ * Either real DMA *or* pseudo DMA may be implemented
+ * REAL functions :
+ * NCR5380_REAL_DMA should be defined if real DMA is to be used.
+ * Note that the DMA setup functions should return the number of bytes
+ * that they were able to program the controller for.
+ *
+ * Also note that generic i386/PC versions of these macros are
+ * available as NCR5380_i386_dma_write_setup,
+ * NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
+ *
+ * NCR5380_dma_write_setup(instance, src, count) - initialize
+ * NCR5380_dma_read_setup(instance, dst, count) - initialize
+ * NCR5380_dma_residual(instance); - residual count
+ *
+ * PSEUDO functions :
+ * NCR5380_pwrite(instance, src, count)
+ * NCR5380_pread(instance, dst, count);
+ *
+ * The generic driver is initialized by calling NCR5380_init(instance),
+ * after setting the appropriate host specific fields and ID. If the
+ * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
+ * possible) function may be used.
+ */
+
+/* Macros ease life... :-) */
+#define SETUP_HOSTDATA(in) \
+ struct NCR5380_hostdata *hostdata = \
+ (struct NCR5380_hostdata *)(in)->hostdata
+#define HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata)
+
+#define NEXT(cmd) ((struct scsi_cmnd *)(cmd)->host_scribble)
+#define SET_NEXT(cmd,next) ((cmd)->host_scribble = (void *)(next))
+#define NEXTADDR(cmd) ((struct scsi_cmnd **)&(cmd)->host_scribble)
+
+#define HOSTNO instance->host_no
+#define H_NO(cmd) (cmd)->device->host->host_no
+
+#ifdef SUPPORT_TAGS
+
+/*
+ * Functions for handling tagged queuing
+ * =====================================
+ *
+ * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
+ *
+ * Using consecutive numbers for the tags is no good idea in my eyes. There
+ * could be wrong re-usings if the counter (8 bit!) wraps and some early
+ * command has been preempted for a long time. My solution: a bitfield for
+ * remembering used tags.
+ *
+ * There's also the problem that each target has a certain queue size, but we
+ * cannot know it in advance :-( We just see a QUEUE_FULL status being
+ * returned. So, in this case, the driver internal queue size assumption is
+ * reduced to the number of active tags if QUEUE_FULL is returned by the
+ * target. The command is returned to the mid-level, but with status changed
+ * to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL
+ * correctly.
+ *
+ * We're also not allowed running tagged commands as long as an untagged
+ * command is active. And REQUEST SENSE commands after a contingent allegiance
+ * condition _must_ be untagged. To keep track whether an untagged command has
+ * been issued, the host->busy array is still employed, as it is without
+ * support for tagged queuing.
+ *
+ * One could suspect that there are possible race conditions between
+ * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
+ * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
+ * which already guaranteed to be running at most once. It is also the only
+ * place where tags/LUNs are allocated. So no other allocation can slip
+ * between that pair, there could only happen a reselection, which can free a
+ * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
+ * important: the tag bit must be cleared before 'nr_allocated' is decreased.
+ */
+
+static void __init init_tags(struct NCR5380_hostdata *hostdata)
+{
+ int target, lun;
+ struct tag_alloc *ta;
+
+ if (!(hostdata->flags & FLAG_TAGGED_QUEUING))
+ return;
+
+ for (target = 0; target < 8; ++target) {
+ for (lun = 0; lun < 8; ++lun) {
+ ta = &hostdata->TagAlloc[target][lun];
+ bitmap_zero(ta->allocated, MAX_TAGS);
+ ta->nr_allocated = 0;
+ /* At the beginning, assume the maximum queue size we could
+ * support (MAX_TAGS). This value will be decreased if the target
+ * returns QUEUE_FULL status.
+ */
+ ta->queue_size = MAX_TAGS;
+ }
+ }
+}
+
+
+/* Check if we can issue a command to this LUN: First see if the LUN is marked
+ * busy by an untagged command. If the command should use tagged queuing, also
+ * check that there is a free tag and the target's queue won't overflow. This
+ * function should be called with interrupts disabled to avoid race
+ * conditions.
+ */
+
+static int is_lun_busy(struct scsi_cmnd *cmd, int should_be_tagged)
+{
+ u8 lun = cmd->device->lun;
+ SETUP_HOSTDATA(cmd->device->host);
+
+ if (hostdata->busy[cmd->device->id] & (1 << lun))
+ return 1;
+ if (!should_be_tagged ||
+ !(hostdata->flags & FLAG_TAGGED_QUEUING) ||
+ !cmd->device->tagged_supported)
+ return 0;
+ if (hostdata->TagAlloc[scmd_id(cmd)][lun].nr_allocated >=
+ hostdata->TagAlloc[scmd_id(cmd)][lun].queue_size) {
+ dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d: no free tags\n",
+ H_NO(cmd), cmd->device->id, lun);
+ return 1;
+ }
+ return 0;
+}
+
+
+/* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
+ * must be called before!), or reserve the LUN in 'busy' if the command is
+ * untagged.
+ */
+
+static void cmd_get_tag(struct scsi_cmnd *cmd, int should_be_tagged)
+{
+ u8 lun = cmd->device->lun;
+ SETUP_HOSTDATA(cmd->device->host);
+
+ /* If we or the target don't support tagged queuing, allocate the LUN for
+ * an untagged command.
+ */
+ if (!should_be_tagged ||
+ !(hostdata->flags & FLAG_TAGGED_QUEUING) ||
+ !cmd->device->tagged_supported) {
+ cmd->tag = TAG_NONE;
+ hostdata->busy[cmd->device->id] |= (1 << lun);
+ dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d now allocated by untagged "
+ "command\n", H_NO(cmd), cmd->device->id, lun);
+ } else {
+ struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][lun];
+
+ cmd->tag = find_first_zero_bit(ta->allocated, MAX_TAGS);
+ set_bit(cmd->tag, ta->allocated);
+ ta->nr_allocated++;
+ dprintk(NDEBUG_TAGS, "scsi%d: using tag %d for target %d lun %d "
+ "(now %d tags in use)\n",
+ H_NO(cmd), cmd->tag, cmd->device->id,
+ lun, ta->nr_allocated);
+ }
+}
+
+
+/* Mark the tag of command 'cmd' as free, or in case of an untagged command,
+ * unlock the LUN.
+ */
+
+static void cmd_free_tag(struct scsi_cmnd *cmd)
+{
+ u8 lun = cmd->device->lun;
+ SETUP_HOSTDATA(cmd->device->host);
+
+ if (cmd->tag == TAG_NONE) {
+ hostdata->busy[cmd->device->id] &= ~(1 << lun);
+ dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d untagged cmd finished\n",
+ H_NO(cmd), cmd->device->id, lun);
+ } else if (cmd->tag >= MAX_TAGS) {
+ printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n",
+ H_NO(cmd), cmd->tag);
+ } else {
+ struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][lun];
+ clear_bit(cmd->tag, ta->allocated);
+ ta->nr_allocated--;
+ dprintk(NDEBUG_TAGS, "scsi%d: freed tag %d for target %d lun %d\n",
+ H_NO(cmd), cmd->tag, cmd->device->id, lun);
+ }
+}
+
+
+static void free_all_tags(struct NCR5380_hostdata *hostdata)
+{
+ int target, lun;
+ struct tag_alloc *ta;
+
+ if (!(hostdata->flags & FLAG_TAGGED_QUEUING))
+ return;
+
+ for (target = 0; target < 8; ++target) {
+ for (lun = 0; lun < 8; ++lun) {
+ ta = &hostdata->TagAlloc[target][lun];
+ bitmap_zero(ta->allocated, MAX_TAGS);
+ ta->nr_allocated = 0;
+ }
+ }
+}
+
+#endif /* SUPPORT_TAGS */
+
+
+/*
+ * Function: void merge_contiguous_buffers( struct scsi_cmnd *cmd )
+ *
+ * Purpose: Try to merge several scatter-gather requests into one DMA
+ * transfer. This is possible if the scatter buffers lie on
+ * physical contiguous addresses.
+ *
+ * Parameters: struct scsi_cmnd *cmd
+ * The command to work on. The first scatter buffer's data are
+ * assumed to be already transferred into ptr/this_residual.
+ */
+
+static void merge_contiguous_buffers(struct scsi_cmnd *cmd)
+{
+#if !defined(CONFIG_SUN3)
+ unsigned long endaddr;
+#if (NDEBUG & NDEBUG_MERGING)
+ unsigned long oldlen = cmd->SCp.this_residual;
+ int cnt = 1;
+#endif
+
+ for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
+ cmd->SCp.buffers_residual &&
+ virt_to_phys(sg_virt(&cmd->SCp.buffer[1])) == endaddr;) {
+ dprintk(NDEBUG_MERGING, "VTOP(%p) == %08lx -> merging\n",
+ page_address(sg_page(&cmd->SCp.buffer[1])), endaddr);
+#if (NDEBUG & NDEBUG_MERGING)
+ ++cnt;
+#endif
+ ++cmd->SCp.buffer;
+ --cmd->SCp.buffers_residual;
+ cmd->SCp.this_residual += cmd->SCp.buffer->length;
+ endaddr += cmd->SCp.buffer->length;
+ }
+#if (NDEBUG & NDEBUG_MERGING)
+ if (oldlen != cmd->SCp.this_residual)
+ dprintk(NDEBUG_MERGING, "merged %d buffers from %p, new length %08x\n",
+ cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
+#endif
+#endif /* !defined(CONFIG_SUN3) */
+}
+
+/**
+ * initialize_SCp - init the scsi pointer field
+ * @cmd: command block to set up
+ *
+ * Set up the internal fields in the SCSI command.
+ */
+
+static inline void initialize_SCp(struct scsi_cmnd *cmd)
+{
+ /*
+ * Initialize the Scsi Pointer field so that all of the commands in the
+ * various queues are valid.
+ */
+
+ if (scsi_bufflen(cmd)) {
+ cmd->SCp.buffer = scsi_sglist(cmd);
+ cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
+ cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
+ cmd->SCp.this_residual = cmd->SCp.buffer->length;
+ /* ++roman: Try to merge some scatter-buffers if they are at
+ * contiguous physical addresses.
+ */
+ merge_contiguous_buffers(cmd);
+ } else {
+ cmd->SCp.buffer = NULL;
+ cmd->SCp.buffers_residual = 0;
+ cmd->SCp.ptr = NULL;
+ cmd->SCp.this_residual = 0;
+ }
+}
+
+#include <linux/delay.h>
+
+#if NDEBUG
+static struct {
+ unsigned char mask;
+ const char *name;
+} signals[] = {
+ { SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" },
+ { SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD, "CD" }, { SR_IO, "IO" },
+ { SR_SEL, "SEL" }, {0, NULL}
+}, basrs[] = {
+ {BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}
+}, icrs[] = {
+ {ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"},
+ {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"},
+ {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"},
+ {0, NULL}
+}, mrs[] = {
+ {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"},
+ {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR,
+ "MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
+ {MR_MONITOR_BSY, "MODE MONITOR BSY"},
+ {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"},
+ {0, NULL}
+};
+
+/**
+ * NCR5380_print - print scsi bus signals
+ * @instance: adapter state to dump
+ *
+ * Print the SCSI bus signals for debugging purposes
+ */
+
+static void NCR5380_print(struct Scsi_Host *instance)
+{
+ unsigned char status, data, basr, mr, icr, i;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ data = NCR5380_read(CURRENT_SCSI_DATA_REG);
+ status = NCR5380_read(STATUS_REG);
+ mr = NCR5380_read(MODE_REG);
+ icr = NCR5380_read(INITIATOR_COMMAND_REG);
+ basr = NCR5380_read(BUS_AND_STATUS_REG);
+ local_irq_restore(flags);
+ printk("STATUS_REG: %02x ", status);
+ for (i = 0; signals[i].mask; ++i)
+ if (status & signals[i].mask)
+ printk(",%s", signals[i].name);
+ printk("\nBASR: %02x ", basr);
+ for (i = 0; basrs[i].mask; ++i)
+ if (basr & basrs[i].mask)
+ printk(",%s", basrs[i].name);
+ printk("\nICR: %02x ", icr);
+ for (i = 0; icrs[i].mask; ++i)
+ if (icr & icrs[i].mask)
+ printk(",%s", icrs[i].name);
+ printk("\nMODE: %02x ", mr);
+ for (i = 0; mrs[i].mask; ++i)
+ if (mr & mrs[i].mask)
+ printk(",%s", mrs[i].name);
+ printk("\n");
+}
+
+static struct {
+ unsigned char value;
+ const char *name;
+} phases[] = {
+ {PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"},
+ {PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"},
+ {PHASE_UNKNOWN, "UNKNOWN"}
+};
+
+/**
+ * NCR5380_print_phase - show SCSI phase
+ * @instance: adapter to dump
+ *
+ * Print the current SCSI phase for debugging purposes
+ *
+ * Locks: none
+ */
+
+static void NCR5380_print_phase(struct Scsi_Host *instance)
+{
+ unsigned char status;
+ int i;
+
+ status = NCR5380_read(STATUS_REG);
+ if (!(status & SR_REQ))
+ printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO);
+ else {
+ for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
+ (phases[i].value != (status & PHASE_MASK)); ++i)
+ ;
+ printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name);
+ }
+}
+
+#endif
+
+/*
+ * ++roman: New scheme of calling NCR5380_main()
+ *
+ * If we're not in an interrupt, we can call our main directly, it cannot be
+ * already running. Else, we queue it on a task queue, if not 'main_running'
+ * tells us that a lower level is already executing it. This way,
+ * 'main_running' needs not be protected in a special way.
+ *
+ * queue_main() is a utility function for putting our main onto the task
+ * queue, if main_running is false. It should be called only from a
+ * interrupt or bottom half.
+ */
+
+#include <linux/gfp.h>
+#include <linux/workqueue.h>
+#include <linux/interrupt.h>
+
+static inline void queue_main(struct NCR5380_hostdata *hostdata)
+{
+ if (!hostdata->main_running) {
+ /* If in interrupt and NCR5380_main() not already running,
+ queue it on the 'immediate' task queue, to be processed
+ immediately after the current interrupt processing has
+ finished. */
+ schedule_work(&hostdata->main_task);
+ }
+ /* else: nothing to do: the running NCR5380_main() will pick up
+ any newly queued command. */
+}
+
+/**
+ * NCR58380_info - report driver and host information
+ * @instance: relevant scsi host instance
+ *
+ * For use as the host template info() handler.
+ *
+ * Locks: none
+ */
+
+static const char *NCR5380_info(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+
+ return hostdata->info;
+}
+
+static void prepare_info(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+
+ snprintf(hostdata->info, sizeof(hostdata->info),
+ "%s, io_port 0x%lx, n_io_port %d, "
+ "base 0x%lx, irq %d, "
+ "can_queue %d, cmd_per_lun %d, "
+ "sg_tablesize %d, this_id %d, "
+ "flags { %s}, "
+ "options { %s} ",
+ instance->hostt->name, instance->io_port, instance->n_io_port,
+ instance->base, instance->irq,
+ instance->can_queue, instance->cmd_per_lun,
+ instance->sg_tablesize, instance->this_id,
+ hostdata->flags & FLAG_TAGGED_QUEUING ? "TAGGED_QUEUING " : "",
+#ifdef DIFFERENTIAL
+ "DIFFERENTIAL "
+#endif
+#ifdef REAL_DMA
+ "REAL_DMA "
+#endif
+#ifdef PARITY
+ "PARITY "
+#endif
+#ifdef SUPPORT_TAGS
+ "SUPPORT_TAGS "
+#endif
+ "");
+}
+
+/**
+ * NCR5380_print_status - dump controller info
+ * @instance: controller to dump
+ *
+ * Print commands in the various queues, called from NCR5380_abort
+ * to aid debugging.
+ */
+
+static void lprint_Scsi_Cmnd(struct scsi_cmnd *cmd)
+{
+ int i, s;
+ unsigned char *command;
+ printk("scsi%d: destination target %d, lun %llu\n",
+ H_NO(cmd), cmd->device->id, cmd->device->lun);
+ printk(KERN_CONT " command = ");
+ command = cmd->cmnd;
+ printk(KERN_CONT "%2d (0x%02x)", command[0], command[0]);
+ for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
+ printk(KERN_CONT " %02x", command[i]);
+ printk("\n");
+}
+
+static void NCR5380_print_status(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata;
+ struct scsi_cmnd *ptr;
+ unsigned long flags;
+
+ NCR5380_dprint(NDEBUG_ANY, instance);
+ NCR5380_dprint_phase(NDEBUG_ANY, instance);
+
+ hostdata = (struct NCR5380_hostdata *)instance->hostdata;
+
+ local_irq_save(flags);
+ printk("NCR5380: coroutine is%s running.\n",
+ hostdata->main_running ? "" : "n't");
+ if (!hostdata->connected)
+ printk("scsi%d: no currently connected command\n", HOSTNO);
+ else
+ lprint_Scsi_Cmnd((struct scsi_cmnd *) hostdata->connected);
+ printk("scsi%d: issue_queue\n", HOSTNO);
+ for (ptr = (struct scsi_cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
+ lprint_Scsi_Cmnd(ptr);
+
+ printk("scsi%d: disconnected_queue\n", HOSTNO);
+ for (ptr = (struct scsi_cmnd *) hostdata->disconnected_queue; ptr;
+ ptr = NEXT(ptr))
+ lprint_Scsi_Cmnd(ptr);
+
+ local_irq_restore(flags);
+ printk("\n");
+}
+
+static void show_Scsi_Cmnd(struct scsi_cmnd *cmd, struct seq_file *m)
+{
+ int i, s;
+ unsigned char *command;
+ seq_printf(m, "scsi%d: destination target %d, lun %llu\n",
+ H_NO(cmd), cmd->device->id, cmd->device->lun);
+ seq_puts(m, " command = ");
+ command = cmd->cmnd;
+ seq_printf(m, "%2d (0x%02x)", command[0], command[0]);
+ for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
+ seq_printf(m, " %02x", command[i]);
+ seq_putc(m, '\n');
+}
+
+static int __maybe_unused NCR5380_show_info(struct seq_file *m,
+ struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata;
+ struct scsi_cmnd *ptr;
+ unsigned long flags;
+
+ hostdata = (struct NCR5380_hostdata *)instance->hostdata;
+
+ local_irq_save(flags);
+ seq_printf(m, "NCR5380: coroutine is%s running.\n",
+ hostdata->main_running ? "" : "n't");
+ if (!hostdata->connected)
+ seq_printf(m, "scsi%d: no currently connected command\n", HOSTNO);
+ else
+ show_Scsi_Cmnd((struct scsi_cmnd *) hostdata->connected, m);
+ seq_printf(m, "scsi%d: issue_queue\n", HOSTNO);
+ for (ptr = (struct scsi_cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
+ show_Scsi_Cmnd(ptr, m);
+
+ seq_printf(m, "scsi%d: disconnected_queue\n", HOSTNO);
+ for (ptr = (struct scsi_cmnd *) hostdata->disconnected_queue; ptr;
+ ptr = NEXT(ptr))
+ show_Scsi_Cmnd(ptr, m);
+
+ local_irq_restore(flags);
+ return 0;
+}
+
+/**
+ * NCR5380_init - initialise an NCR5380
+ * @instance: adapter to configure
+ * @flags: control flags
+ *
+ * Initializes *instance and corresponding 5380 chip,
+ * with flags OR'd into the initial flags value.
+ *
+ * Notes : I assume that the host, hostno, and id bits have been
+ * set correctly. I don't care about the irq and other fields.
+ *
+ * Returns 0 for success
+ */
+
+static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
+{
+ int i;
+ SETUP_HOSTDATA(instance);
+
+ hostdata->host = instance;
+ hostdata->aborted = 0;
+ hostdata->id_mask = 1 << instance->this_id;
+ hostdata->id_higher_mask = 0;
+ for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
+ if (i > hostdata->id_mask)
+ hostdata->id_higher_mask |= i;
+ for (i = 0; i < 8; ++i)
+ hostdata->busy[i] = 0;
+#ifdef SUPPORT_TAGS
+ init_tags(hostdata);
+#endif
+#if defined (REAL_DMA)
+ hostdata->dma_len = 0;
+#endif
+ hostdata->targets_present = 0;
+ hostdata->connected = NULL;
+ hostdata->issue_queue = NULL;
+ hostdata->disconnected_queue = NULL;
+ hostdata->flags = flags;
+
+ INIT_WORK(&hostdata->main_task, NCR5380_main);
+
+ prepare_info(instance);
+
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ NCR5380_write(MODE_REG, MR_BASE);
+ NCR5380_write(TARGET_COMMAND_REG, 0);
+ NCR5380_write(SELECT_ENABLE_REG, 0);
+
+ return 0;
+}
+
+/**
+ * NCR5380_exit - remove an NCR5380
+ * @instance: adapter to remove
+ *
+ * Assumes that no more work can be queued (e.g. by NCR5380_intr).
+ */
+
+static void NCR5380_exit(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+
+ cancel_work_sync(&hostdata->main_task);
+}
+
+/**
+ * NCR5380_queue_command - queue a command
+ * @instance: the relevant SCSI adapter
+ * @cmd: SCSI command
+ *
+ * cmd is added to the per instance issue_queue, with minor
+ * twiddling done to the host specific fields of cmd. If the
+ * main coroutine is not running, it is restarted.
+ */
+
+static int NCR5380_queue_command(struct Scsi_Host *instance,
+ struct scsi_cmnd *cmd)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ struct scsi_cmnd *tmp;
+ unsigned long flags;
+
+#if (NDEBUG & NDEBUG_NO_WRITE)
+ switch (cmd->cmnd[0]) {
+ case WRITE_6:
+ case WRITE_10:
+ printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
+ H_NO(cmd));
+ cmd->result = (DID_ERROR << 16);
+ cmd->scsi_done(cmd);
+ return 0;
+ }
+#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
+
+ /*
+ * We use the host_scribble field as a pointer to the next command
+ * in a queue
+ */
+
+ SET_NEXT(cmd, NULL);
+ cmd->result = 0;
+
+ /*
+ * Insert the cmd into the issue queue. Note that REQUEST SENSE
+ * commands are added to the head of the queue since any command will
+ * clear the contingent allegiance condition that exists and the
+ * sense data is only guaranteed to be valid while the condition exists.
+ */
+
+ /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
+ * Otherwise a running NCR5380_main may steal the lock.
+ * Lock before actually inserting due to fairness reasons explained in
+ * atari_scsi.c. If we insert first, then it's impossible for this driver
+ * to release the lock.
+ * Stop timer for this command while waiting for the lock, or timeouts
+ * may happen (and they really do), and it's no good if the command doesn't
+ * appear in any of the queues.
+ * ++roman: Just disabling the NCR interrupt isn't sufficient here,
+ * because also a timer int can trigger an abort or reset, which would
+ * alter queues and touch the lock.
+ */
+ if (!NCR5380_acquire_dma_irq(instance))
+ return SCSI_MLQUEUE_HOST_BUSY;
+
+ local_irq_save(flags);
+
+ /*
+ * Insert the cmd into the issue queue. Note that REQUEST SENSE
+ * commands are added to the head of the queue since any command will
+ * clear the contingent allegiance condition that exists and the
+ * sense data is only guaranteed to be valid while the condition exists.
+ */
+
+ if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
+ LIST(cmd, hostdata->issue_queue);
+ SET_NEXT(cmd, hostdata->issue_queue);
+ hostdata->issue_queue = cmd;
+ } else {
+ for (tmp = (struct scsi_cmnd *)hostdata->issue_queue;
+ NEXT(tmp); tmp = NEXT(tmp))
+ ;
+ LIST(cmd, tmp);
+ SET_NEXT(tmp, cmd);
+ }
+ local_irq_restore(flags);
+
+ dprintk(NDEBUG_QUEUES, "scsi%d: command added to %s of queue\n", H_NO(cmd),
+ (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
+
+ /* If queue_command() is called from an interrupt (real one or bottom
+ * half), we let queue_main() do the job of taking care about main. If it
+ * is already running, this is a no-op, else main will be queued.
+ *
+ * If we're not in an interrupt, we can call NCR5380_main()
+ * unconditionally, because it cannot be already running.
+ */
+ if (in_interrupt() || irqs_disabled())
+ queue_main(hostdata);
+ else
+ NCR5380_main(&hostdata->main_task);
+ return 0;
+}
+
+static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+
+ /* Caller does the locking needed to set & test these data atomically */
+ if (!hostdata->disconnected_queue &&
+ !hostdata->issue_queue &&
+ !hostdata->connected &&
+ !hostdata->retain_dma_intr)
+ NCR5380_release_dma_irq(instance);
+}
+
+/**
+ * NCR5380_main - NCR state machines
+ *
+ * NCR5380_main is a coroutine that runs as long as more work can
+ * be done on the NCR5380 host adapters in a system. Both
+ * NCR5380_queue_command() and NCR5380_intr() will try to start it
+ * in case it is not running.
+ *
+ * Locks: called as its own thread with no locks held.
+ */
+
+static void NCR5380_main(struct work_struct *work)
+{
+ struct NCR5380_hostdata *hostdata =
+ container_of(work, struct NCR5380_hostdata, main_task);
+ struct Scsi_Host *instance = hostdata->host;
+ struct scsi_cmnd *tmp, *prev;
+ int done;
+ unsigned long flags;
+
+ /*
+ * We run (with interrupts disabled) until we're sure that none of
+ * the host adapters have anything that can be done, at which point
+ * we set main_running to 0 and exit.
+ *
+ * Interrupts are enabled before doing various other internal
+ * instructions, after we've decided that we need to run through
+ * the loop again.
+ *
+ * this should prevent any race conditions.
+ *
+ * ++roman: Just disabling the NCR interrupt isn't sufficient here,
+ * because also a timer int can trigger an abort or reset, which can
+ * alter queues and touch the Falcon lock.
+ */
+
+ /* Tell int handlers main() is now already executing. Note that
+ no races are possible here. If an int comes in before
+ 'main_running' is set here, and queues/executes main via the
+ task queue, it doesn't do any harm, just this instance of main
+ won't find any work left to do. */
+ if (hostdata->main_running)
+ return;
+ hostdata->main_running = 1;
+
+ local_save_flags(flags);
+ do {
+ local_irq_disable(); /* Freeze request queues */
+ done = 1;
+
+ if (!hostdata->connected) {
+ dprintk(NDEBUG_MAIN, "scsi%d: not connected\n", HOSTNO);
+ /*
+ * Search through the issue_queue for a command destined
+ * for a target that's not busy.
+ */
+#if (NDEBUG & NDEBUG_LISTS)
+ for (tmp = (struct scsi_cmnd *) hostdata->issue_queue, prev = NULL;
+ tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
+ ;
+ /*printk("%p ", tmp);*/
+ if ((tmp == prev) && tmp)
+ printk(" LOOP\n");
+ /* else printk("\n"); */
+#endif
+ for (tmp = (struct scsi_cmnd *) hostdata->issue_queue,
+ prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
+ u8 lun = tmp->device->lun;
+
+ dprintk(NDEBUG_LISTS,
+ "MAIN tmp=%p target=%d busy=%d lun=%d\n",
+ tmp, scmd_id(tmp), hostdata->busy[scmd_id(tmp)],
+ lun);
+ /* When we find one, remove it from the issue queue. */
+ /* ++guenther: possible race with Falcon locking */
+ if (
+#ifdef SUPPORT_TAGS
+ !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
+#else
+ !(hostdata->busy[tmp->device->id] & (1 << lun))
+#endif
+ ) {
+ /* ++guenther: just to be sure, this must be atomic */
+ local_irq_disable();
+ if (prev) {
+ REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
+ SET_NEXT(prev, NEXT(tmp));
+ } else {
+ REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
+ hostdata->issue_queue = NEXT(tmp);
+ }
+ SET_NEXT(tmp, NULL);
+ hostdata->retain_dma_intr++;
+
+ /* reenable interrupts after finding one */
+ local_irq_restore(flags);
+
+ /*
+ * Attempt to establish an I_T_L nexus here.
+ * On success, instance->hostdata->connected is set.
+ * On failure, we must add the command back to the
+ * issue queue so we can keep trying.
+ */
+ dprintk(NDEBUG_MAIN, "scsi%d: main(): command for target %d "
+ "lun %d removed from issue_queue\n",
+ HOSTNO, tmp->device->id, lun);
+ /*
+ * REQUEST SENSE commands are issued without tagged
+ * queueing, even on SCSI-II devices because the
+ * contingent allegiance condition exists for the
+ * entire unit.
+ */
+ /* ++roman: ...and the standard also requires that
+ * REQUEST SENSE command are untagged.
+ */
+
+#ifdef SUPPORT_TAGS
+ cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
+#endif
+ if (!NCR5380_select(instance, tmp)) {
+ local_irq_disable();
+ hostdata->retain_dma_intr--;
+ /* release if target did not response! */
+ maybe_release_dma_irq(instance);
+ local_irq_restore(flags);
+ break;
+ } else {
+ local_irq_disable();
+ LIST(tmp, hostdata->issue_queue);
+ SET_NEXT(tmp, hostdata->issue_queue);
+ hostdata->issue_queue = tmp;
+#ifdef SUPPORT_TAGS
+ cmd_free_tag(tmp);
+#endif
+ hostdata->retain_dma_intr--;
+ local_irq_restore(flags);
+ dprintk(NDEBUG_MAIN, "scsi%d: main(): select() failed, "
+ "returned to issue_queue\n", HOSTNO);
+ if (hostdata->connected)
+ break;
+ }
+ } /* if target/lun/target queue is not busy */
+ } /* for issue_queue */
+ } /* if (!hostdata->connected) */
+
+ if (hostdata->connected
+#ifdef REAL_DMA
+ && !hostdata->dma_len
+#endif
+ ) {
+ local_irq_restore(flags);
+ dprintk(NDEBUG_MAIN, "scsi%d: main: performing information transfer\n",
+ HOSTNO);
+ NCR5380_information_transfer(instance);
+ dprintk(NDEBUG_MAIN, "scsi%d: main: done set false\n", HOSTNO);
+ done = 0;
+ }
+ } while (!done);
+
+ /* Better allow ints _after_ 'main_running' has been cleared, else
+ an interrupt could believe we'll pick up the work it left for
+ us, but we won't see it anymore here... */
+ hostdata->main_running = 0;
+ local_irq_restore(flags);
+}
+
+
+#ifdef REAL_DMA
+/*
+ * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
+ *
+ * Purpose : Called by interrupt handler when DMA finishes or a phase
+ * mismatch occurs (which would finish the DMA transfer).
+ *
+ * Inputs : instance - this instance of the NCR5380.
+ *
+ */
+
+static void NCR5380_dma_complete(struct Scsi_Host *instance)
+{
+ SETUP_HOSTDATA(instance);
+ int transferred;
+ unsigned char **data;
+ volatile int *count;
+ int saved_data = 0, overrun = 0;
+ unsigned char p;
+
+ if (!hostdata->connected) {
+ printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
+ "no connected cmd\n", HOSTNO);
+ return;
+ }
+
+ if (hostdata->read_overruns) {
+ p = hostdata->connected->SCp.phase;
+ if (p & SR_IO) {
+ udelay(10);
+ if ((NCR5380_read(BUS_AND_STATUS_REG) &
+ (BASR_PHASE_MATCH|BASR_ACK)) ==
+ (BASR_PHASE_MATCH|BASR_ACK)) {
+ saved_data = NCR5380_read(INPUT_DATA_REG);
+ overrun = 1;
+ dprintk(NDEBUG_DMA, "scsi%d: read overrun handled\n", HOSTNO);
+ }
+ }
+ }
+
+ dprintk(NDEBUG_DMA, "scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
+ HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
+ NCR5380_read(STATUS_REG));
+
+#if defined(CONFIG_SUN3)
+ if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
+ pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
+ instance->host_no);
+ BUG();
+ }
+
+ /* make sure we're not stuck in a data phase */
+ if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
+ (BASR_PHASE_MATCH | BASR_ACK)) {
+ pr_err("scsi%d: BASR %02x\n", instance->host_no,
+ NCR5380_read(BUS_AND_STATUS_REG));
+ pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
+ instance->host_no);
+ BUG();
+ }
+#endif
+
+ (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ NCR5380_write(MODE_REG, MR_BASE);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+
+ transferred = hostdata->dma_len - NCR5380_dma_residual(instance);
+ hostdata->dma_len = 0;
+
+ data = (unsigned char **)&hostdata->connected->SCp.ptr;
+ count = &hostdata->connected->SCp.this_residual;
+ *data += transferred;
+ *count -= transferred;
+
+ if (hostdata->read_overruns) {
+ int cnt, toPIO;
+
+ if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
+ cnt = toPIO = hostdata->read_overruns;
+ if (overrun) {
+ dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
+ *(*data)++ = saved_data;
+ (*count)--;
+ cnt--;
+ toPIO--;
+ }
+ dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
+ NCR5380_transfer_pio(instance, &p, &cnt, data);
+ *count -= toPIO - cnt;
+ }
+ }
+}
+#endif /* REAL_DMA */
+
+
+/**
+ * NCR5380_intr - generic NCR5380 irq handler
+ * @irq: interrupt number
+ * @dev_id: device info
+ *
+ * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
+ * from the disconnected queue, and restarting NCR5380_main()
+ * as required.
+ */
+
+static irqreturn_t NCR5380_intr(int irq, void *dev_id)
+{
+ struct Scsi_Host *instance = dev_id;
+ int done = 1, handled = 0;
+ unsigned char basr;
+
+ dprintk(NDEBUG_INTR, "scsi%d: NCR5380 irq triggered\n", HOSTNO);
+
+ /* Look for pending interrupts */
+ basr = NCR5380_read(BUS_AND_STATUS_REG);
+ dprintk(NDEBUG_INTR, "scsi%d: BASR=%02x\n", HOSTNO, basr);
+ /* dispatch to appropriate routine if found and done=0 */
+ if (basr & BASR_IRQ) {
+ NCR5380_dprint(NDEBUG_INTR, instance);
+ if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
+ done = 0;
+ dprintk(NDEBUG_INTR, "scsi%d: SEL interrupt\n", HOSTNO);
+ NCR5380_reselect(instance);
+ (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ } else if (basr & BASR_PARITY_ERROR) {
+ dprintk(NDEBUG_INTR, "scsi%d: PARITY interrupt\n", HOSTNO);
+ (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
+ dprintk(NDEBUG_INTR, "scsi%d: RESET interrupt\n", HOSTNO);
+ (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ } else {
+ /*
+ * The rest of the interrupt conditions can occur only during a
+ * DMA transfer
+ */
+
+#if defined(REAL_DMA)
+ /*
+ * We should only get PHASE MISMATCH and EOP interrupts if we have
+ * DMA enabled, so do a sanity check based on the current setting
+ * of the MODE register.
+ */
+
+ if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
+ ((basr & BASR_END_DMA_TRANSFER) ||
+ !(basr & BASR_PHASE_MATCH))) {
+
+ dprintk(NDEBUG_INTR, "scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
+ NCR5380_dma_complete( instance );
+ done = 0;
+ } else
+#endif /* REAL_DMA */
+ {
+/* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
+ if (basr & BASR_PHASE_MATCH)
+ dprintk(NDEBUG_INTR, "scsi%d: unknown interrupt, "
+ "BASR 0x%x, MR 0x%x, SR 0x%x\n",
+ HOSTNO, basr, NCR5380_read(MODE_REG),
+ NCR5380_read(STATUS_REG));
+ (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_DMA_ENABLE;
+#endif
+ }
+ } /* if !(SELECTION || PARITY) */
+ handled = 1;
+ } /* BASR & IRQ */ else {
+ printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
+ "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
+ NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
+ (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_DMA_ENABLE;
+#endif
+ }
+
+ if (!done) {
+ dprintk(NDEBUG_INTR, "scsi%d: in int routine, calling main\n", HOSTNO);
+ /* Put a call to NCR5380_main() on the queue... */
+ queue_main(shost_priv(instance));
+ }
+ return IRQ_RETVAL(handled);
+}
+
+/*
+ * Function : int NCR5380_select(struct Scsi_Host *instance,
+ * struct scsi_cmnd *cmd)
+ *
+ * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
+ * including ARBITRATION, SELECTION, and initial message out for
+ * IDENTIFY and queue messages.
+ *
+ * Inputs : instance - instantiation of the 5380 driver on which this
+ * target lives, cmd - SCSI command to execute.
+ *
+ * Returns : -1 if selection could not execute for some reason,
+ * 0 if selection succeeded or failed because the target
+ * did not respond.
+ *
+ * Side effects :
+ * If bus busy, arbitration failed, etc, NCR5380_select() will exit
+ * with registers as they should have been on entry - ie
+ * SELECT_ENABLE will be set appropriately, the NCR5380
+ * will cease to drive any SCSI bus signals.
+ *
+ * If successful : I_T_L or I_T_L_Q nexus will be established,
+ * instance->connected will be set to cmd.
+ * SELECT interrupt will be disabled.
+ *
+ * If failed (no target) : cmd->scsi_done() will be called, and the
+ * cmd->result host byte set to DID_BAD_TARGET.
+ */
+
+static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
+{
+ SETUP_HOSTDATA(instance);
+ unsigned char tmp[3], phase;
+ unsigned char *data;
+ int len;
+ unsigned long timeout;
+ unsigned long flags;
+
+ hostdata->restart_select = 0;
+ NCR5380_dprint(NDEBUG_ARBITRATION, instance);
+ dprintk(NDEBUG_ARBITRATION, "scsi%d: starting arbitration, id = %d\n", HOSTNO,
+ instance->this_id);
+
+ /*
+ * Set the phase bits to 0, otherwise the NCR5380 won't drive the
+ * data bus during SELECTION.
+ */
+
+ local_irq_save(flags);
+ if (hostdata->connected) {
+ local_irq_restore(flags);
+ return -1;
+ }
+ NCR5380_write(TARGET_COMMAND_REG, 0);
+
+ /*
+ * Start arbitration.
+ */
+
+ NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
+ NCR5380_write(MODE_REG, MR_ARBITRATE);
+
+ local_irq_restore(flags);
+
+ /* Wait for arbitration logic to complete */
+#if defined(NCR_TIMEOUT)
+ {
+ unsigned long timeout = jiffies + 2*NCR_TIMEOUT;
+
+ while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
+ time_before(jiffies, timeout) && !hostdata->connected)
+ ;
+ if (time_after_eq(jiffies, timeout)) {
+ printk("scsi : arbitration timeout at %d\n", __LINE__);
+ NCR5380_write(MODE_REG, MR_BASE);
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ return -1;
+ }
+ }
+#else /* NCR_TIMEOUT */
+ while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
+ !hostdata->connected)
+ ;
+#endif
+
+ dprintk(NDEBUG_ARBITRATION, "scsi%d: arbitration complete\n", HOSTNO);
+
+ if (hostdata->connected) {
+ NCR5380_write(MODE_REG, MR_BASE);
+ return -1;
+ }
+ /*
+ * The arbitration delay is 2.2us, but this is a minimum and there is
+ * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
+ * the integral nature of udelay().
+ *
+ */
+
+ udelay(3);
+
+ /* Check for lost arbitration */
+ if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
+ (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
+ (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
+ hostdata->connected) {
+ NCR5380_write(MODE_REG, MR_BASE);
+ dprintk(NDEBUG_ARBITRATION, "scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
+ HOSTNO);
+ return -1;
+ }
+
+ /* after/during arbitration, BSY should be asserted.
+ IBM DPES-31080 Version S31Q works now */
+ /* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
+ NCR5380_write(INITIATOR_COMMAND_REG,
+ ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
+
+ if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
+ hostdata->connected) {
+ NCR5380_write(MODE_REG, MR_BASE);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ dprintk(NDEBUG_ARBITRATION, "scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
+ HOSTNO);
+ return -1;
+ }
+
+ /*
+ * Again, bus clear + bus settle time is 1.2us, however, this is
+ * a minimum so we'll udelay ceil(1.2)
+ */
+
+#ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
+ /* ++roman: But some targets (see above :-) seem to need a bit more... */
+ udelay(15);
+#else
+ udelay(2);
+#endif
+
+ if (hostdata->connected) {
+ NCR5380_write(MODE_REG, MR_BASE);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ return -1;
+ }
+
+ dprintk(NDEBUG_ARBITRATION, "scsi%d: won arbitration\n", HOSTNO);
+
+ /*
+ * Now that we have won arbitration, start Selection process, asserting
+ * the host and target ID's on the SCSI bus.
+ */
+
+ NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));
+
+ /*
+ * Raise ATN while SEL is true before BSY goes false from arbitration,
+ * since this is the only way to guarantee that we'll get a MESSAGE OUT
+ * phase immediately after selection.
+ */
+
+ NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY |
+ ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
+ NCR5380_write(MODE_REG, MR_BASE);
+
+ /*
+ * Reselect interrupts must be turned off prior to the dropping of BSY,
+ * otherwise we will trigger an interrupt.
+ */
+
+ if (hostdata->connected) {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ return -1;
+ }
+
+ NCR5380_write(SELECT_ENABLE_REG, 0);
+
+ /*
+ * The initiator shall then wait at least two deskew delays and release
+ * the BSY signal.
+ */
+ udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */
+
+ /* Reset BSY */
+ NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA |
+ ICR_ASSERT_ATN | ICR_ASSERT_SEL));
+
+ /*
+ * Something weird happens when we cease to drive BSY - looks
+ * like the board/chip is letting us do another read before the
+ * appropriate propagation delay has expired, and we're confusing
+ * a BSY signal from ourselves as the target's response to SELECTION.
+ *
+ * A small delay (the 'C++' frontend breaks the pipeline with an
+ * unnecessary jump, making it work on my 386-33/Trantor T128, the
+ * tighter 'C' code breaks and requires this) solves the problem -
+ * the 1 us delay is arbitrary, and only used because this delay will
+ * be the same on other platforms and since it works here, it should
+ * work there.
+ *
+ * wingel suggests that this could be due to failing to wait
+ * one deskew delay.
+ */
+
+ udelay(1);
+
+ dprintk(NDEBUG_SELECTION, "scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
+
+ /*
+ * The SCSI specification calls for a 250 ms timeout for the actual
+ * selection.
+ */
+
+ timeout = jiffies + msecs_to_jiffies(250);
+
+ /*
+ * XXX very interesting - we're seeing a bounce where the BSY we
+ * asserted is being reflected / still asserted (propagation delay?)
+ * and it's detecting as true. Sigh.
+ */
+
+#if 0
+ /* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
+ * IO while SEL is true. But again, there are some disks out the in the
+ * world that do that nevertheless. (Somebody claimed that this announces
+ * reselection capability of the target.) So we better skip that test and
+ * only wait for BSY... (Famous german words: Der Klügere gibt nach :-)
+ */
+
+ while (time_before(jiffies, timeout) &&
+ !(NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO)))
+ ;
+
+ if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ NCR5380_reselect(instance);
+ printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
+ HOSTNO);
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ return -1;
+ }
+#else
+ while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY))
+ ;
+#endif
+
+ /*
+ * No less than two deskew delays after the initiator detects the
+ * BSY signal is true, it shall release the SEL signal and may
+ * change the DATA BUS. -wingel
+ */
+
+ udelay(1);
+
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
+
+ if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ if (hostdata->targets_present & (1 << cmd->device->id)) {
+ printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
+ if (hostdata->restart_select)
+ printk(KERN_NOTICE "\trestart select\n");
+ NCR5380_dprint(NDEBUG_ANY, instance);
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ return -1;
+ }
+ cmd->result = DID_BAD_TARGET << 16;
+#ifdef SUPPORT_TAGS
+ cmd_free_tag(cmd);
+#endif
+ cmd->scsi_done(cmd);
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ dprintk(NDEBUG_SELECTION, "scsi%d: target did not respond within 250ms\n", HOSTNO);
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ return 0;
+ }
+
+ hostdata->targets_present |= (1 << cmd->device->id);
+
+ /*
+ * Since we followed the SCSI spec, and raised ATN while SEL
+ * was true but before BSY was false during selection, the information
+ * transfer phase should be a MESSAGE OUT phase so that we can send the
+ * IDENTIFY message.
+ *
+ * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
+ * message (2 bytes) with a tag ID that we increment with every command
+ * until it wraps back to 0.
+ *
+ * XXX - it turns out that there are some broken SCSI-II devices,
+ * which claim to support tagged queuing but fail when more than
+ * some number of commands are issued at once.
+ */
+
+ /* Wait for start of REQ/ACK handshake */
+ while (!(NCR5380_read(STATUS_REG) & SR_REQ))
+ ;
+
+ dprintk(NDEBUG_SELECTION, "scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
+ HOSTNO, cmd->device->id);
+ tmp[0] = IDENTIFY(1, cmd->device->lun);
+
+#ifdef SUPPORT_TAGS
+ if (cmd->tag != TAG_NONE) {
+ tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
+ tmp[2] = cmd->tag;
+ len = 3;
+ } else
+ len = 1;
+#else
+ len = 1;
+ cmd->tag = 0;
+#endif /* SUPPORT_TAGS */
+
+ /* Send message(s) */
+ data = tmp;
+ phase = PHASE_MSGOUT;
+ NCR5380_transfer_pio(instance, &phase, &len, &data);
+ dprintk(NDEBUG_SELECTION, "scsi%d: nexus established.\n", HOSTNO);
+ /* XXX need to handle errors here */
+ hostdata->connected = cmd;
+#ifndef SUPPORT_TAGS
+ hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
+#endif
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_INTR;
+#endif
+
+ initialize_SCp(cmd);
+
+ return 0;
+}
+
+/*
+ * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
+ * unsigned char *phase, int *count, unsigned char **data)
+ *
+ * Purpose : transfers data in given phase using polled I/O
+ *
+ * Inputs : instance - instance of driver, *phase - pointer to
+ * what phase is expected, *count - pointer to number of
+ * bytes to transfer, **data - pointer to data pointer.
+ *
+ * Returns : -1 when different phase is entered without transferring
+ * maximum number of bytes, 0 if all bytes are transferred or exit
+ * is in same phase.
+ *
+ * Also, *phase, *count, *data are modified in place.
+ *
+ * XXX Note : handling for bus free may be useful.
+ */
+
+/*
+ * Note : this code is not as quick as it could be, however it
+ * IS 100% reliable, and for the actual data transfer where speed
+ * counts, we will always do a pseudo DMA or DMA transfer.
+ */
+
+static int NCR5380_transfer_pio(struct Scsi_Host *instance,
+ unsigned char *phase, int *count,
+ unsigned char **data)
+{
+ register unsigned char p = *phase, tmp;
+ register int c = *count;
+ register unsigned char *d = *data;
+
+ /*
+ * The NCR5380 chip will only drive the SCSI bus when the
+ * phase specified in the appropriate bits of the TARGET COMMAND
+ * REGISTER match the STATUS REGISTER
+ */
+
+ NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
+
+ do {
+ /*
+ * Wait for assertion of REQ, after which the phase bits will be
+ * valid
+ */
+ while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
+ ;
+
+ dprintk(NDEBUG_HANDSHAKE, "scsi%d: REQ detected\n", HOSTNO);
+
+ /* Check for phase mismatch */
+ if ((tmp & PHASE_MASK) != p) {
+ dprintk(NDEBUG_PIO, "scsi%d: phase mismatch\n", HOSTNO);
+ NCR5380_dprint_phase(NDEBUG_PIO, instance);
+ break;
+ }
+
+ /* Do actual transfer from SCSI bus to / from memory */
+ if (!(p & SR_IO))
+ NCR5380_write(OUTPUT_DATA_REG, *d);
+ else
+ *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
+
+ ++d;
+
+ /*
+ * The SCSI standard suggests that in MSGOUT phase, the initiator
+ * should drop ATN on the last byte of the message phase
+ * after REQ has been asserted for the handshake but before
+ * the initiator raises ACK.
+ */
+
+ if (!(p & SR_IO)) {
+ if (!((p & SR_MSG) && c > 1)) {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
+ NCR5380_dprint(NDEBUG_PIO, instance);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
+ ICR_ASSERT_DATA | ICR_ASSERT_ACK);
+ } else {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
+ ICR_ASSERT_DATA | ICR_ASSERT_ATN);
+ NCR5380_dprint(NDEBUG_PIO, instance);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
+ ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
+ }
+ } else {
+ NCR5380_dprint(NDEBUG_PIO, instance);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
+ }
+
+ while (NCR5380_read(STATUS_REG) & SR_REQ)
+ ;
+
+ dprintk(NDEBUG_HANDSHAKE, "scsi%d: req false, handshake complete\n", HOSTNO);
+
+ /*
+ * We have several special cases to consider during REQ/ACK handshaking :
+ * 1. We were in MSGOUT phase, and we are on the last byte of the
+ * message. ATN must be dropped as ACK is dropped.
+ *
+ * 2. We are in a MSGIN phase, and we are on the last byte of the
+ * message. We must exit with ACK asserted, so that the calling
+ * code may raise ATN before dropping ACK to reject the message.
+ *
+ * 3. ACK and ATN are clear and the target may proceed as normal.
+ */
+ if (!(p == PHASE_MSGIN && c == 1)) {
+ if (p == PHASE_MSGOUT && c > 1)
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
+ else
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ }
+ } while (--c);
+
+ dprintk(NDEBUG_PIO, "scsi%d: residual %d\n", HOSTNO, c);
+
+ *count = c;
+ *data = d;
+ tmp = NCR5380_read(STATUS_REG);
+ /* The phase read from the bus is valid if either REQ is (already)
+ * asserted or if ACK hasn't been released yet. The latter is the case if
+ * we're in MSGIN and all wanted bytes have been received.
+ */
+ if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
+ *phase = tmp & PHASE_MASK;
+ else
+ *phase = PHASE_UNKNOWN;
+
+ if (!c || (*phase == p))
+ return 0;
+ else
+ return -1;
+}
+
+/*
+ * Function : do_abort (Scsi_Host *host)
+ *
+ * Purpose : abort the currently established nexus. Should only be
+ * called from a routine which can drop into a
+ *
+ * Returns : 0 on success, -1 on failure.
+ */
+
+static int do_abort(struct Scsi_Host *instance)
+{
+ unsigned char tmp, *msgptr, phase;
+ int len;
+
+ /* Request message out phase */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
+
+ /*
+ * Wait for the target to indicate a valid phase by asserting
+ * REQ. Once this happens, we'll have either a MSGOUT phase
+ * and can immediately send the ABORT message, or we'll have some
+ * other phase and will have to source/sink data.
+ *
+ * We really don't care what value was on the bus or what value
+ * the target sees, so we just handshake.
+ */
+
+ while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
+ ;
+
+ NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
+
+ if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
+ ICR_ASSERT_ACK);
+ while (NCR5380_read(STATUS_REG) & SR_REQ)
+ ;
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
+ }
+
+ tmp = ABORT;
+ msgptr = &tmp;
+ len = 1;
+ phase = PHASE_MSGOUT;
+ NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
+
+ /*
+ * If we got here, and the command completed successfully,
+ * we're about to go into bus free state.
+ */
+
+ return len ? -1 : 0;
+}
+
+#if defined(REAL_DMA)
+/*
+ * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
+ * unsigned char *phase, int *count, unsigned char **data)
+ *
+ * Purpose : transfers data in given phase using either real
+ * or pseudo DMA.
+ *
+ * Inputs : instance - instance of driver, *phase - pointer to
+ * what phase is expected, *count - pointer to number of
+ * bytes to transfer, **data - pointer to data pointer.
+ *
+ * Returns : -1 when different phase is entered without transferring
+ * maximum number of bytes, 0 if all bytes or transferred or exit
+ * is in same phase.
+ *
+ * Also, *phase, *count, *data are modified in place.
+ *
+ */
+
+
+static int NCR5380_transfer_dma(struct Scsi_Host *instance,
+ unsigned char *phase, int *count,
+ unsigned char **data)
+{
+ SETUP_HOSTDATA(instance);
+ register int c = *count;
+ register unsigned char p = *phase;
+ unsigned long flags;
+
+#if defined(CONFIG_SUN3)
+ /* sanity check */
+ if (!sun3_dma_setup_done) {
+ pr_err("scsi%d: transfer_dma without setup!\n",
+ instance->host_no);
+ BUG();
+ }
+ hostdata->dma_len = c;
+
+ dprintk(NDEBUG_DMA, "scsi%d: initializing DMA for %s, %d bytes %s %p\n",
+ instance->host_no, (p & SR_IO) ? "reading" : "writing",
+ c, (p & SR_IO) ? "to" : "from", *data);
+
+ /* netbsd turns off ints here, why not be safe and do it too */
+ local_irq_save(flags);
+
+ /* send start chain */
+ sun3scsi_dma_start(c, *data);
+
+ if (p & SR_IO) {
+ NCR5380_write(TARGET_COMMAND_REG, 1);
+ NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ NCR5380_write(INITIATOR_COMMAND_REG, 0);
+ NCR5380_write(MODE_REG,
+ (NCR5380_read(MODE_REG) | MR_DMA_MODE | MR_ENABLE_EOP_INTR));
+ NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
+ } else {
+ NCR5380_write(TARGET_COMMAND_REG, 0);
+ NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_DATA);
+ NCR5380_write(MODE_REG,
+ (NCR5380_read(MODE_REG) | MR_DMA_MODE | MR_ENABLE_EOP_INTR));
+ NCR5380_write(START_DMA_SEND_REG, 0);
+ }
+
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_DMA_ENABLE;
+#endif
+
+ local_irq_restore(flags);
+
+ sun3_dma_active = 1;
+
+#else /* !defined(CONFIG_SUN3) */
+ register unsigned char *d = *data;
+ unsigned char tmp;
+
+ if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
+ *phase = tmp;
+ return -1;
+ }
+
+ if (hostdata->read_overruns && (p & SR_IO))
+ c -= hostdata->read_overruns;
+
+ dprintk(NDEBUG_DMA, "scsi%d: initializing DMA for %s, %d bytes %s %p\n",
+ HOSTNO, (p & SR_IO) ? "reading" : "writing",
+ c, (p & SR_IO) ? "to" : "from", d);
+
+ NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
+
+#ifdef REAL_DMA
+ NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
+#endif /* def REAL_DMA */
+
+ if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
+ /* On the Medusa, it is a must to initialize the DMA before
+ * starting the NCR. This is also the cleaner way for the TT.
+ */
+ local_irq_save(flags);
+ hostdata->dma_len = (p & SR_IO) ?
+ NCR5380_dma_read_setup(instance, d, c) :
+ NCR5380_dma_write_setup(instance, d, c);
+ local_irq_restore(flags);
+ }
+
+ if (p & SR_IO)
+ NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
+ else {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
+ NCR5380_write(START_DMA_SEND_REG, 0);
+ }
+
+ if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
+ /* On the Falcon, the DMA setup must be done after the last */
+ /* NCR access, else the DMA setup gets trashed!
+ */
+ local_irq_save(flags);
+ hostdata->dma_len = (p & SR_IO) ?
+ NCR5380_dma_read_setup(instance, d, c) :
+ NCR5380_dma_write_setup(instance, d, c);
+ local_irq_restore(flags);
+ }
+#endif /* !defined(CONFIG_SUN3) */
+
+ return 0;
+}
+#endif /* defined(REAL_DMA) */
+
+/*
+ * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
+ *
+ * Purpose : run through the various SCSI phases and do as the target
+ * directs us to. Operates on the currently connected command,
+ * instance->connected.
+ *
+ * Inputs : instance, instance for which we are doing commands
+ *
+ * Side effects : SCSI things happen, the disconnected queue will be
+ * modified if a command disconnects, *instance->connected will
+ * change.
+ *
+ * XXX Note : we need to watch for bus free or a reset condition here
+ * to recover from an unexpected bus free condition.
+ */
+
+static void NCR5380_information_transfer(struct Scsi_Host *instance)
+{
+ SETUP_HOSTDATA(instance);
+ unsigned long flags;
+ unsigned char msgout = NOP;
+ int sink = 0;
+ int len;
+#if defined(REAL_DMA)
+ int transfersize;
+#endif
+ unsigned char *data;
+ unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
+ struct scsi_cmnd *cmd = (struct scsi_cmnd *) hostdata->connected;
+
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_INTR;
+#endif
+
+ while (1) {
+ tmp = NCR5380_read(STATUS_REG);
+ /* We only have a valid SCSI phase when REQ is asserted */
+ if (tmp & SR_REQ) {
+ phase = (tmp & PHASE_MASK);
+ if (phase != old_phase) {
+ old_phase = phase;
+ NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
+ }
+#if defined(CONFIG_SUN3)
+ if (phase == PHASE_CMDOUT) {
+#if defined(REAL_DMA)
+ void *d;
+ unsigned long count;
+
+ if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
+ count = cmd->SCp.buffer->length;
+ d = sg_virt(cmd->SCp.buffer);
+ } else {
+ count = cmd->SCp.this_residual;
+ d = cmd->SCp.ptr;
+ }
+ /* this command setup for dma yet? */
+ if ((count >= DMA_MIN_SIZE) && (sun3_dma_setup_done != cmd)) {
+ if (cmd->request->cmd_type == REQ_TYPE_FS) {
+ sun3scsi_dma_setup(d, count,
+ rq_data_dir(cmd->request));
+ sun3_dma_setup_done = cmd;
+ }
+ }
+#endif
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_INTR;
+#endif
+ }
+#endif /* CONFIG_SUN3 */
+
+ if (sink && (phase != PHASE_MSGOUT)) {
+ NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
+
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
+ ICR_ASSERT_ACK);
+ while (NCR5380_read(STATUS_REG) & SR_REQ)
+ ;
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
+ ICR_ASSERT_ATN);
+ sink = 0;
+ continue;
+ }
+
+ switch (phase) {
+ case PHASE_DATAOUT:
+#if (NDEBUG & NDEBUG_NO_DATAOUT)
+ printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
+ "aborted\n", HOSTNO);
+ sink = 1;
+ do_abort(instance);
+ cmd->result = DID_ERROR << 16;
+ cmd->scsi_done(cmd);
+ return;
+#endif
+ case PHASE_DATAIN:
+ /*
+ * If there is no room left in the current buffer in the
+ * scatter-gather list, move onto the next one.
+ */
+
+ if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
+ ++cmd->SCp.buffer;
+ --cmd->SCp.buffers_residual;
+ cmd->SCp.this_residual = cmd->SCp.buffer->length;
+ cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
+ /* ++roman: Try to merge some scatter-buffers if
+ * they are at contiguous physical addresses.
+ */
+ merge_contiguous_buffers(cmd);
+ dprintk(NDEBUG_INFORMATION, "scsi%d: %d bytes and %d buffers left\n",
+ HOSTNO, cmd->SCp.this_residual,
+ cmd->SCp.buffers_residual);
+ }
+
+ /*
+ * The preferred transfer method is going to be
+ * PSEUDO-DMA for systems that are strictly PIO,
+ * since we can let the hardware do the handshaking.
+ *
+ * For this to work, we need to know the transfersize
+ * ahead of time, since the pseudo-DMA code will sit
+ * in an unconditional loop.
+ */
+
+ /* ++roman: I suggest, this should be
+ * #if def(REAL_DMA)
+ * instead of leaving REAL_DMA out.
+ */
+
+#if defined(REAL_DMA)
+ if (
+#if !defined(CONFIG_SUN3)
+ !cmd->device->borken &&
+#endif
+ (transfersize = NCR5380_dma_xfer_len(instance, cmd, phase)) >= DMA_MIN_SIZE) {
+ len = transfersize;
+ cmd->SCp.phase = phase;
+ if (NCR5380_transfer_dma(instance, &phase,
+ &len, (unsigned char **)&cmd->SCp.ptr)) {
+ /*
+ * If the watchdog timer fires, all future
+ * accesses to this device will use the
+ * polled-IO. */
+ scmd_printk(KERN_INFO, cmd,
+ "switching to slow handshake\n");
+ cmd->device->borken = 1;
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
+ ICR_ASSERT_ATN);
+ sink = 1;
+ do_abort(instance);
+ cmd->result = DID_ERROR << 16;
+ cmd->scsi_done(cmd);
+ /* XXX - need to source or sink data here, as appropriate */
+ } else {
+#ifdef REAL_DMA
+ /* ++roman: When using real DMA,
+ * information_transfer() should return after
+ * starting DMA since it has nothing more to
+ * do.
+ */
+ return;
+#else
+ cmd->SCp.this_residual -= transfersize - len;
+#endif
+ }
+ } else
+#endif /* defined(REAL_DMA) */
+ NCR5380_transfer_pio(instance, &phase,
+ (int *)&cmd->SCp.this_residual,
+ (unsigned char **)&cmd->SCp.ptr);
+#if defined(CONFIG_SUN3) && defined(REAL_DMA)
+ /* if we had intended to dma that command clear it */
+ if (sun3_dma_setup_done == cmd)
+ sun3_dma_setup_done = NULL;
+#endif
+ break;
+ case PHASE_MSGIN:
+ len = 1;
+ data = &tmp;
+ NCR5380_write(SELECT_ENABLE_REG, 0); /* disable reselects */
+ NCR5380_transfer_pio(instance, &phase, &len, &data);
+ cmd->SCp.Message = tmp;
+
+ switch (tmp) {
+ /*
+ * Linking lets us reduce the time required to get the
+ * next command out to the device, hopefully this will
+ * mean we don't waste another revolution due to the delays
+ * required by ARBITRATION and another SELECTION.
+ *
+ * In the current implementation proposal, low level drivers
+ * merely have to start the next command, pointed to by
+ * next_link, done() is called as with unlinked commands.
+ */
+#ifdef LINKED
+ case LINKED_CMD_COMPLETE:
+ case LINKED_FLG_CMD_COMPLETE:
+ /* Accept message by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+
+ dprintk(NDEBUG_LINKED, "scsi%d: target %d lun %llu linked command "
+ "complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);
+
+ /* Enable reselect interrupts */
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ /*
+ * Sanity check : A linked command should only terminate
+ * with one of these messages if there are more linked
+ * commands available.
+ */
+
+ if (!cmd->next_link) {
+ printk(KERN_NOTICE "scsi%d: target %d lun %llu "
+ "linked command complete, no next_link\n",
+ HOSTNO, cmd->device->id, cmd->device->lun);
+ sink = 1;
+ do_abort(instance);
+ return;
+ }
+
+ initialize_SCp(cmd->next_link);
+ /* The next command is still part of this process; copy it
+ * and don't free it! */
+ cmd->next_link->tag = cmd->tag;
+ cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
+ dprintk(NDEBUG_LINKED, "scsi%d: target %d lun %llu linked request "
+ "done, calling scsi_done().\n",
+ HOSTNO, cmd->device->id, cmd->device->lun);
+ cmd->scsi_done(cmd);
+ cmd = hostdata->connected;
+ break;
+#endif /* def LINKED */
+ case ABORT:
+ case COMMAND_COMPLETE:
+ /* Accept message by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ dprintk(NDEBUG_QUEUES, "scsi%d: command for target %d, lun %llu "
+ "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
+
+ local_irq_save(flags);
+ hostdata->retain_dma_intr++;
+ hostdata->connected = NULL;
+#ifdef SUPPORT_TAGS
+ cmd_free_tag(cmd);
+ if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
+ /* Turn a QUEUE FULL status into BUSY, I think the
+ * mid level cannot handle QUEUE FULL :-( (The
+ * command is retried after BUSY). Also update our
+ * queue size to the number of currently issued
+ * commands now.
+ */
+ /* ++Andreas: the mid level code knows about
+ QUEUE_FULL now. */
+ struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][cmd->device->lun];
+ dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %llu returned "
+ "QUEUE_FULL after %d commands\n",
+ HOSTNO, cmd->device->id, cmd->device->lun,
+ ta->nr_allocated);
+ if (ta->queue_size > ta->nr_allocated)
+ ta->nr_allocated = ta->queue_size;
+ }
+#else
+ hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
+#endif
+ /* Enable reselect interrupts */
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+
+ /*
+ * I'm not sure what the correct thing to do here is :
+ *
+ * If the command that just executed is NOT a request
+ * sense, the obvious thing to do is to set the result
+ * code to the values of the stored parameters.
+ *
+ * If it was a REQUEST SENSE command, we need some way to
+ * differentiate between the failure code of the original
+ * and the failure code of the REQUEST sense - the obvious
+ * case is success, where we fall through and leave the
+ * result code unchanged.
+ *
+ * The non-obvious place is where the REQUEST SENSE failed
+ */
+
+ if (cmd->cmnd[0] != REQUEST_SENSE)
+ cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
+ else if (status_byte(cmd->SCp.Status) != GOOD)
+ cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
+
+ if ((cmd->cmnd[0] == REQUEST_SENSE) &&
+ hostdata->ses.cmd_len) {
+ scsi_eh_restore_cmnd(cmd, &hostdata->ses);
+ hostdata->ses.cmd_len = 0 ;
+ }
+
+ if ((cmd->cmnd[0] != REQUEST_SENSE) &&
+ (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
+ scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
+
+ dprintk(NDEBUG_AUTOSENSE, "scsi%d: performing request sense\n", HOSTNO);
+
+ LIST(cmd,hostdata->issue_queue);
+ SET_NEXT(cmd, hostdata->issue_queue);
+ hostdata->issue_queue = (struct scsi_cmnd *) cmd;
+ dprintk(NDEBUG_QUEUES, "scsi%d: REQUEST SENSE added to head of "
+ "issue queue\n", H_NO(cmd));
+ } else {
+ cmd->scsi_done(cmd);
+ }
+
+ local_irq_restore(flags);
+
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ /*
+ * Restore phase bits to 0 so an interrupted selection,
+ * arbitration can resume.
+ */
+ NCR5380_write(TARGET_COMMAND_REG, 0);
+
+ while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
+ barrier();
+
+ local_irq_save(flags);
+ hostdata->retain_dma_intr--;
+ /* ++roman: For Falcon SCSI, release the lock on the
+ * ST-DMA here if no other commands are waiting on the
+ * disconnected queue.
+ */
+ maybe_release_dma_irq(instance);
+ local_irq_restore(flags);
+ return;
+ case MESSAGE_REJECT:
+ /* Accept message by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ /* Enable reselect interrupts */
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ switch (hostdata->last_message) {
+ case HEAD_OF_QUEUE_TAG:
+ case ORDERED_QUEUE_TAG:
+ case SIMPLE_QUEUE_TAG:
+ /* The target obviously doesn't support tagged
+ * queuing, even though it announced this ability in
+ * its INQUIRY data ?!? (maybe only this LUN?) Ok,
+ * clear 'tagged_supported' and lock the LUN, since
+ * the command is treated as untagged further on.
+ */
+ cmd->device->tagged_supported = 0;
+ hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
+ cmd->tag = TAG_NONE;
+ dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %llu rejected "
+ "QUEUE_TAG message; tagged queuing "
+ "disabled\n",
+ HOSTNO, cmd->device->id, cmd->device->lun);
+ break;
+ }
+ break;
+ case DISCONNECT:
+ /* Accept message by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ local_irq_save(flags);
+ cmd->device->disconnect = 1;
+ LIST(cmd,hostdata->disconnected_queue);
+ SET_NEXT(cmd, hostdata->disconnected_queue);
+ hostdata->connected = NULL;
+ hostdata->disconnected_queue = cmd;
+ local_irq_restore(flags);
+ dprintk(NDEBUG_QUEUES, "scsi%d: command for target %d lun %llu was "
+ "moved from connected to the "
+ "disconnected_queue\n", HOSTNO,
+ cmd->device->id, cmd->device->lun);
+ /*
+ * Restore phase bits to 0 so an interrupted selection,
+ * arbitration can resume.
+ */
+ NCR5380_write(TARGET_COMMAND_REG, 0);
+
+ /* Enable reselect interrupts */
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ /* Wait for bus free to avoid nasty timeouts */
+ while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
+ barrier();
+#ifdef SUN3_SCSI_VME
+ dregs->csr |= CSR_DMA_ENABLE;
+#endif
+ return;
+ /*
+ * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
+ * operation, in violation of the SCSI spec so we can safely
+ * ignore SAVE/RESTORE pointers calls.
+ *
+ * Unfortunately, some disks violate the SCSI spec and
+ * don't issue the required SAVE_POINTERS message before
+ * disconnecting, and we have to break spec to remain
+ * compatible.
+ */
+ case SAVE_POINTERS:
+ case RESTORE_POINTERS:
+ /* Accept message by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ /* Enable reselect interrupts */
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ break;
+ case EXTENDED_MESSAGE:
+ /*
+ * Extended messages are sent in the following format :
+ * Byte
+ * 0 EXTENDED_MESSAGE == 1
+ * 1 length (includes one byte for code, doesn't
+ * include first two bytes)
+ * 2 code
+ * 3..length+1 arguments
+ *
+ * Start the extended message buffer with the EXTENDED_MESSAGE
+ * byte, since spi_print_msg() wants the whole thing.
+ */
+ extended_msg[0] = EXTENDED_MESSAGE;
+ /* Accept first byte by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+
+ dprintk(NDEBUG_EXTENDED, "scsi%d: receiving extended message\n", HOSTNO);
+
+ len = 2;
+ data = extended_msg + 1;
+ phase = PHASE_MSGIN;
+ NCR5380_transfer_pio(instance, &phase, &len, &data);
+ dprintk(NDEBUG_EXTENDED, "scsi%d: length=%d, code=0x%02x\n", HOSTNO,
+ (int)extended_msg[1], (int)extended_msg[2]);
+
+ if (!len && extended_msg[1] <=
+ (sizeof(extended_msg) - 1)) {
+ /* Accept third byte by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ len = extended_msg[1] - 1;
+ data = extended_msg + 3;
+ phase = PHASE_MSGIN;
+
+ NCR5380_transfer_pio(instance, &phase, &len, &data);
+ dprintk(NDEBUG_EXTENDED, "scsi%d: message received, residual %d\n",
+ HOSTNO, len);
+
+ switch (extended_msg[2]) {
+ case EXTENDED_SDTR:
+ case EXTENDED_WDTR:
+ case EXTENDED_MODIFY_DATA_POINTER:
+ case EXTENDED_EXTENDED_IDENTIFY:
+ tmp = 0;
+ }
+ } else if (len) {
+ printk(KERN_NOTICE "scsi%d: error receiving "
+ "extended message\n", HOSTNO);
+ tmp = 0;
+ } else {
+ printk(KERN_NOTICE "scsi%d: extended message "
+ "code %02x length %d is too long\n",
+ HOSTNO, extended_msg[2], extended_msg[1]);
+ tmp = 0;
+ }
+ /* Fall through to reject message */
+
+ /*
+ * If we get something weird that we aren't expecting,
+ * reject it.
+ */
+ default:
+ if (!tmp) {
+ printk(KERN_INFO "scsi%d: rejecting message ",
+ instance->host_no);
+ spi_print_msg(extended_msg);
+ printk("\n");
+ } else if (tmp != EXTENDED_MESSAGE)
+ scmd_printk(KERN_INFO, cmd,
+ "rejecting unknown message %02x\n",
+ tmp);
+ else
+ scmd_printk(KERN_INFO, cmd,
+ "rejecting unknown extended message code %02x, length %d\n",
+ extended_msg[1], extended_msg[0]);
+
+ msgout = MESSAGE_REJECT;
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
+ break;
+ } /* switch (tmp) */
+ break;
+ case PHASE_MSGOUT:
+ len = 1;
+ data = &msgout;
+ hostdata->last_message = msgout;
+ NCR5380_transfer_pio(instance, &phase, &len, &data);
+ if (msgout == ABORT) {
+ local_irq_save(flags);
+#ifdef SUPPORT_TAGS
+ cmd_free_tag(cmd);
+#else
+ hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
+#endif
+ hostdata->connected = NULL;
+ cmd->result = DID_ERROR << 16;
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+ maybe_release_dma_irq(instance);
+ local_irq_restore(flags);
+ cmd->scsi_done(cmd);
+ return;
+ }
+ msgout = NOP;
+ break;
+ case PHASE_CMDOUT:
+ len = cmd->cmd_len;
+ data = cmd->cmnd;
+ /*
+ * XXX for performance reasons, on machines with a
+ * PSEUDO-DMA architecture we should probably
+ * use the dma transfer function.
+ */
+ NCR5380_transfer_pio(instance, &phase, &len, &data);
+ break;
+ case PHASE_STATIN:
+ len = 1;
+ data = &tmp;
+ NCR5380_transfer_pio(instance, &phase, &len, &data);
+ cmd->SCp.Status = tmp;
+ break;
+ default:
+ printk("scsi%d: unknown phase\n", HOSTNO);
+ NCR5380_dprint(NDEBUG_ANY, instance);
+ } /* switch(phase) */
+ } /* if (tmp * SR_REQ) */
+ } /* while (1) */
+}
+
+/*
+ * Function : void NCR5380_reselect (struct Scsi_Host *instance)
+ *
+ * Purpose : does reselection, initializing the instance->connected
+ * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
+ * nexus has been reestablished,
+ *
+ * Inputs : instance - this instance of the NCR5380.
+ *
+ */
+
+
+/* it might eventually prove necessary to do a dma setup on
+ reselection, but it doesn't seem to be needed now -- sam */
+
+static void NCR5380_reselect(struct Scsi_Host *instance)
+{
+ SETUP_HOSTDATA(instance);
+ unsigned char target_mask;
+ unsigned char lun;
+#ifdef SUPPORT_TAGS
+ unsigned char tag;
+#endif
+ unsigned char msg[3];
+ int __maybe_unused len;
+ unsigned char __maybe_unused *data, __maybe_unused phase;
+ struct scsi_cmnd *tmp = NULL, *prev;
+
+ /*
+ * Disable arbitration, etc. since the host adapter obviously
+ * lost, and tell an interrupted NCR5380_select() to restart.
+ */
+
+ NCR5380_write(MODE_REG, MR_BASE);
+ hostdata->restart_select = 1;
+
+ target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
+
+ dprintk(NDEBUG_RESELECTION, "scsi%d: reselect\n", HOSTNO);
+
+ /*
+ * At this point, we have detected that our SCSI ID is on the bus,
+ * SEL is true and BSY was false for at least one bus settle delay
+ * (400 ns).
+ *
+ * We must assert BSY ourselves, until the target drops the SEL
+ * signal.
+ */
+
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
+
+ while (NCR5380_read(STATUS_REG) & SR_SEL)
+ ;
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+
+ /*
+ * Wait for target to go into MSGIN.
+ */
+
+ while (!(NCR5380_read(STATUS_REG) & SR_REQ))
+ ;
+
+#if defined(CONFIG_SUN3) && defined(REAL_DMA)
+ /* acknowledge toggle to MSGIN */
+ NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
+
+ /* peek at the byte without really hitting the bus */
+ msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
+#else
+ len = 1;
+ data = msg;
+ phase = PHASE_MSGIN;
+ NCR5380_transfer_pio(instance, &phase, &len, &data);
+#endif
+
+ if (!(msg[0] & 0x80)) {
+ printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
+ spi_print_msg(msg);
+ do_abort(instance);
+ return;
+ }
+ lun = (msg[0] & 0x07);
+
+#if defined(SUPPORT_TAGS) && !defined(CONFIG_SUN3)
+ /* If the phase is still MSGIN, the target wants to send some more
+ * messages. In case it supports tagged queuing, this is probably a
+ * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
+ */
+ tag = TAG_NONE;
+ if (phase == PHASE_MSGIN && (hostdata->flags & FLAG_TAGGED_QUEUING)) {
+ /* Accept previous IDENTIFY message by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ len = 2;
+ data = msg + 1;
+ if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
+ msg[1] == SIMPLE_QUEUE_TAG)
+ tag = msg[2];
+ dprintk(NDEBUG_TAGS, "scsi%d: target mask %02x, lun %d sent tag %d at "
+ "reselection\n", HOSTNO, target_mask, lun, tag);
+ }
+#endif
+
+ /*
+ * Find the command corresponding to the I_T_L or I_T_L_Q nexus we
+ * just reestablished, and remove it from the disconnected queue.
+ */
+
+ for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue, prev = NULL;
+ tmp; prev = tmp, tmp = NEXT(tmp)) {
+ if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
+#ifdef SUPPORT_TAGS
+ && (tag == tmp->tag)
+#endif
+ ) {
+ if (prev) {
+ REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
+ SET_NEXT(prev, NEXT(tmp));
+ } else {
+ REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
+ hostdata->disconnected_queue = NEXT(tmp);
+ }
+ SET_NEXT(tmp, NULL);
+ break;
+ }
+ }
+
+ if (!tmp) {
+ printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
+#ifdef SUPPORT_TAGS
+ "tag %d "
+#endif
+ "not in disconnected_queue.\n",
+ HOSTNO, target_mask, lun
+#ifdef SUPPORT_TAGS
+ , tag
+#endif
+ );
+ /*
+ * Since we have an established nexus that we can't do anything
+ * with, we must abort it.
+ */
+ do_abort(instance);
+ return;
+ }
+
+#if defined(CONFIG_SUN3) && defined(REAL_DMA)
+ /* engage dma setup for the command we just saw */
+ {
+ void *d;
+ unsigned long count;
+
+ if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
+ count = tmp->SCp.buffer->length;
+ d = sg_virt(tmp->SCp.buffer);
+ } else {
+ count = tmp->SCp.this_residual;
+ d = tmp->SCp.ptr;
+ }
+ /* setup this command for dma if not already */
+ if ((count >= DMA_MIN_SIZE) && (sun3_dma_setup_done != tmp)) {
+ sun3scsi_dma_setup(d, count, rq_data_dir(tmp->request));
+ sun3_dma_setup_done = tmp;
+ }
+ }
+
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
+#endif
+
+ /* Accept message by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+
+#if defined(SUPPORT_TAGS) && defined(CONFIG_SUN3)
+ /* If the phase is still MSGIN, the target wants to send some more
+ * messages. In case it supports tagged queuing, this is probably a
+ * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
+ */
+ tag = TAG_NONE;
+ if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
+ /* Accept previous IDENTIFY message by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ len = 2;
+ data = msg + 1;
+ if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
+ msg[1] == SIMPLE_QUEUE_TAG)
+ tag = msg[2];
+ dprintk(NDEBUG_TAGS, "scsi%d: target mask %02x, lun %d sent tag %d at reselection\n"
+ HOSTNO, target_mask, lun, tag);
+ }
+#endif
+
+ hostdata->connected = tmp;
+ dprintk(NDEBUG_RESELECTION, "scsi%d: nexus established, target = %d, lun = %llu, tag = %d\n",
+ HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
+}
+
+
+/*
+ * Function : int NCR5380_abort (struct scsi_cmnd *cmd)
+ *
+ * Purpose : abort a command
+ *
+ * Inputs : cmd - the scsi_cmnd to abort, code - code to set the
+ * host byte of the result field to, if zero DID_ABORTED is
+ * used.
+ *
+ * Returns : SUCCESS - success, FAILED on failure.
+ *
+ * XXX - there is no way to abort the command that is currently
+ * connected, you have to wait for it to complete. If this is
+ * a problem, we could implement longjmp() / setjmp(), setjmp()
+ * called where the loop started in NCR5380_main().
+ */
+
+static
+int NCR5380_abort(struct scsi_cmnd *cmd)
+{
+ struct Scsi_Host *instance = cmd->device->host;
+ SETUP_HOSTDATA(instance);
+ struct scsi_cmnd *tmp, **prev;
+ unsigned long flags;
+
+ scmd_printk(KERN_NOTICE, cmd, "aborting command\n");
+
+ NCR5380_print_status(instance);
+
+ local_irq_save(flags);
+
+ dprintk(NDEBUG_ABORT, "scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
+ NCR5380_read(BUS_AND_STATUS_REG),
+ NCR5380_read(STATUS_REG));
+
+#if 1
+ /*
+ * Case 1 : If the command is the currently executing command,
+ * we'll set the aborted flag and return control so that
+ * information transfer routine can exit cleanly.
+ */
+
+ if (hostdata->connected == cmd) {
+
+ dprintk(NDEBUG_ABORT, "scsi%d: aborting connected command\n", HOSTNO);
+ /*
+ * We should perform BSY checking, and make sure we haven't slipped
+ * into BUS FREE.
+ */
+
+ /* NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
+ /*
+ * Since we can't change phases until we've completed the current
+ * handshake, we have to source or sink a byte of data if the current
+ * phase is not MSGOUT.
+ */
+
+ /*
+ * Return control to the executing NCR drive so we can clear the
+ * aborted flag and get back into our main loop.
+ */
+
+ if (do_abort(instance) == 0) {
+ hostdata->aborted = 1;
+ hostdata->connected = NULL;
+ cmd->result = DID_ABORT << 16;
+#ifdef SUPPORT_TAGS
+ cmd_free_tag(cmd);
+#else
+ hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
+#endif
+ maybe_release_dma_irq(instance);
+ local_irq_restore(flags);
+ cmd->scsi_done(cmd);
+ return SUCCESS;
+ } else {
+ local_irq_restore(flags);
+ printk("scsi%d: abort of connected command failed!\n", HOSTNO);
+ return FAILED;
+ }
+ }
+#endif
+
+ /*
+ * Case 2 : If the command hasn't been issued yet, we simply remove it
+ * from the issue queue.
+ */
+ for (prev = (struct scsi_cmnd **)&(hostdata->issue_queue),
+ tmp = (struct scsi_cmnd *)hostdata->issue_queue;
+ tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
+ if (cmd == tmp) {
+ REMOVE(5, *prev, tmp, NEXT(tmp));
+ (*prev) = NEXT(tmp);
+ SET_NEXT(tmp, NULL);
+ tmp->result = DID_ABORT << 16;
+ maybe_release_dma_irq(instance);
+ local_irq_restore(flags);
+ dprintk(NDEBUG_ABORT, "scsi%d: abort removed command from issue queue.\n",
+ HOSTNO);
+ /* Tagged queuing note: no tag to free here, hasn't been assigned
+ * yet... */
+ tmp->scsi_done(tmp);
+ return SUCCESS;
+ }
+ }
+
+ /*
+ * Case 3 : If any commands are connected, we're going to fail the abort
+ * and let the high level SCSI driver retry at a later time or
+ * issue a reset.
+ *
+ * Timeouts, and therefore aborted commands, will be highly unlikely
+ * and handling them cleanly in this situation would make the common
+ * case of noresets less efficient, and would pollute our code. So,
+ * we fail.
+ */
+
+ if (hostdata->connected) {
+ local_irq_restore(flags);
+ dprintk(NDEBUG_ABORT, "scsi%d: abort failed, command connected.\n", HOSTNO);
+ return FAILED;
+ }
+
+ /*
+ * Case 4: If the command is currently disconnected from the bus, and
+ * there are no connected commands, we reconnect the I_T_L or
+ * I_T_L_Q nexus associated with it, go into message out, and send
+ * an abort message.
+ *
+ * This case is especially ugly. In order to reestablish the nexus, we
+ * need to call NCR5380_select(). The easiest way to implement this
+ * function was to abort if the bus was busy, and let the interrupt
+ * handler triggered on the SEL for reselect take care of lost arbitrations
+ * where necessary, meaning interrupts need to be enabled.
+ *
+ * When interrupts are enabled, the queues may change - so we
+ * can't remove it from the disconnected queue before selecting it
+ * because that could cause a failure in hashing the nexus if that
+ * device reselected.
+ *
+ * Since the queues may change, we can't use the pointers from when we
+ * first locate it.
+ *
+ * So, we must first locate the command, and if NCR5380_select()
+ * succeeds, then issue the abort, relocate the command and remove
+ * it from the disconnected queue.
+ */
+
+ for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue; tmp;
+ tmp = NEXT(tmp)) {
+ if (cmd == tmp) {
+ local_irq_restore(flags);
+ dprintk(NDEBUG_ABORT, "scsi%d: aborting disconnected command.\n", HOSTNO);
+
+ if (NCR5380_select(instance, cmd))
+ return FAILED;
+
+ dprintk(NDEBUG_ABORT, "scsi%d: nexus reestablished.\n", HOSTNO);
+
+ do_abort(instance);
+
+ local_irq_save(flags);
+ for (prev = (struct scsi_cmnd **)&(hostdata->disconnected_queue),
+ tmp = (struct scsi_cmnd *)hostdata->disconnected_queue;
+ tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
+ if (cmd == tmp) {
+ REMOVE(5, *prev, tmp, NEXT(tmp));
+ *prev = NEXT(tmp);
+ SET_NEXT(tmp, NULL);
+ tmp->result = DID_ABORT << 16;
+ /* We must unlock the tag/LUN immediately here, since the
+ * target goes to BUS FREE and doesn't send us another
+ * message (COMMAND_COMPLETE or the like)
+ */
+#ifdef SUPPORT_TAGS
+ cmd_free_tag(tmp);
+#else
+ hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
+#endif
+ maybe_release_dma_irq(instance);
+ local_irq_restore(flags);
+ tmp->scsi_done(tmp);
+ return SUCCESS;
+ }
+ }
+ }
+ }
+
+ /* Maybe it is sufficient just to release the ST-DMA lock... (if
+ * possible at all) At least, we should check if the lock could be
+ * released after the abort, in case it is kept due to some bug.
+ */
+ maybe_release_dma_irq(instance);
+ local_irq_restore(flags);
+
+ /*
+ * Case 5 : If we reached this point, the command was not found in any of
+ * the queues.
+ *
+ * We probably reached this point because of an unlikely race condition
+ * between the command completing successfully and the abortion code,
+ * so we won't panic, but we will notify the user in case something really
+ * broke.
+ */
+
+ printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully before abortion\n", HOSTNO);
+
+ return FAILED;
+}
+
+
+/*
+ * Function : int NCR5380_reset (struct scsi_cmnd *cmd)
+ *
+ * Purpose : reset the SCSI bus.
+ *
+ * Returns : SUCCESS or FAILURE
+ *
+ */
+
+static int NCR5380_bus_reset(struct scsi_cmnd *cmd)
+{
+ struct Scsi_Host *instance = cmd->device->host;
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ int i;
+ unsigned long flags;
+
+ NCR5380_print_status(instance);
+
+ /* get in phase */
+ NCR5380_write(TARGET_COMMAND_REG,
+ PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
+ /* assert RST */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
+ udelay(40);
+ /* reset NCR registers */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ NCR5380_write(MODE_REG, MR_BASE);
+ NCR5380_write(TARGET_COMMAND_REG, 0);
+ NCR5380_write(SELECT_ENABLE_REG, 0);
+ /* ++roman: reset interrupt condition! otherwise no interrupts don't get
+ * through anymore ... */
+ (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+
+ /* After the reset, there are no more connected or disconnected commands
+ * and no busy units; so clear the low-level status here to avoid
+ * conflicts when the mid-level code tries to wake up the affected
+ * commands!
+ */
+
+ if (hostdata->issue_queue)
+ dprintk(NDEBUG_ABORT, "scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
+ if (hostdata->connected)
+ dprintk(NDEBUG_ABORT, "scsi%d: reset aborted a connected command\n", H_NO(cmd));
+ if (hostdata->disconnected_queue)
+ dprintk(NDEBUG_ABORT, "scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));
+
+ local_irq_save(flags);
+ hostdata->issue_queue = NULL;
+ hostdata->connected = NULL;
+ hostdata->disconnected_queue = NULL;
+#ifdef SUPPORT_TAGS
+ free_all_tags(hostdata);
+#endif
+ for (i = 0; i < 8; ++i)
+ hostdata->busy[i] = 0;
+#ifdef REAL_DMA
+ hostdata->dma_len = 0;
+#endif
+
+ maybe_release_dma_irq(instance);
+ local_irq_restore(flags);
+
+ return SUCCESS;
+}